1. Field of Invention
The present invention relates to road markers which provide high target exposure. More particularly, the present invention relates to high target road markers having horizontal orientation of reflective surfaces.
2. Prior Art
Delineation of median islands and other low level road obstructions requires reflective markers which are quickly observable from many orientations. This is particularly true during night driving conditions because the road surface and median curb merge in shadows which are difficult to distinguish.
Many forms of reflector materials and markers have been applied to this difficult delineation area. These include vertical reflectors which provide 360 degree reflection and which may be attached directly to the median island surface. Ideally, such delineators are removable to enable replacement subsequent to damage or wear.
In addition to the tubular delineators previously mentioned horizontal delineation has been applied which supplies a lateral array of reflective material and specifically oriented towards the primary direction of traffic flow. Such horizontal markers are designed to comply with the higher target area of reflective surface specified in MUTCD standards. Obviously, the intent is to quickly catch the attention of a drive, whose headlights pass across the horizontal line of reflective material.
Unfortunately, a disadvantage of the horizontal delineator is the large target area subject to impact by car wheels and vehicles. Instead of a four or five inch wide upright marker, the target area may consist of a horizontal marker extending as much as 12 to 16 inches in width. Such extension increases the likelihood of tire collision by three or four times.
It is essential, therefore, that such delineators develop flexibility which preserves the life of the marker during wheel and vehicle collisions. In addition to flexibility, the marker upright must be resilient to return the marker to its proper orientation after being run over by a vehicle or car wheels. Meeting such criteria with long range survivability is a difficult proposition. Survival rates of current state of the art delineators of this type may run in the matter of only weeks, in high impact zones.
Therefore, what is needed is a highly visible, horizontal delineation device which is adapted to survive frequent impact and at the same time provide for simple installation and replacement.